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Synthesis and Characterization of Bent‐Core Liquid Crystal / Modified γ‐Al 2 O 3 Nanocomposites
Author(s) -
Karabuğa Hande,
Mert Hatice Hande,
Karanlık Gürkan,
Ocak Hale
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201902589
Subject(s) - materials science , liquid crystal , mesophase , nanoparticle , differential scanning calorimetry , ammonium bromide , nanocomposite , crystallography , chemical engineering , thermotropic crystal , scanning electron microscope , nanotechnology , chemistry , pulmonary surfactant , composite material , liquid crystalline , physics , engineering , thermodynamics , optoelectronics
Abstract A new bent‐core liquid crystal (LC) compound CPDB derived from a 4‐chlororesorcinol central core unit with two terephthalate based rod‐like units carrying chiral ( S )‐3,7‐dimethyloctyloxy terminal chains has been synthesized and LC / modified γ‐Al 2 O 3 nanocomposites have been prepared in different compositions. The effects of being doped with 0.3, 0.5, 1.0, 2.0, 3.0 and 4.0% modified γ‐Al 2 O 3 nanoparticles on mesomorphic properties of the new bent‐core liquid crystal, which shows an enantiotropic SmA phase, were investigated by differential scanning calorimetry and optical polarizing microscopy. The surface of γ‐Al 2 O 3 nanoparticles was modified with a cationic agent, cetyltrimethyl ammonium bromide (CTAB), used as a compatibilizer for providing interaction of liquid crystal molecule with alumina nanoparticles. The immobilization of CTAB on γ‐Al 2 O 3 nanoparticle surface via physical adsorption in solution was confirmed by TGA and preserved of crystalline structure of aluminium oxide was proved by XRD analysis. The presence and homogeneous distribution of alumina nanoparticles in LC were confirmed by using Scanning Electron Microscopy (SEM) and energy dispersive X‐ray (EDX) spectroscopy. The modified γ‐Al 2 O 3 nanoparticles in CPDB liquid crystal give rise to a slight increase in the mesomorphic range by preserving mesophase type as observed in pure liquid crystalline compound.